1. Field of the Invention
The present invention relates generally to methods and means for attaching extrusions and the like to frame members, as for example for attaching various kinds and types of horizontal supporting members to side frames of a nature commonly used in business machines and the like.
2. Description of the Prior Art
As is well known in the mechanical arts, many different methods and means have been utilized for attaching extrusions and other types of formed members to frame structures, such methods and means involving a wide variety of schemes of varying degrees of complexity. A common motive underlying the provocating inventive effort that has given rise to such variety of arrangements has been the desire to achieve a completely reliable connection between such members at minimal material and labor costs.
Typical of the prior art methods and means for attaching extrusions and the like to frame members are those illustrated in FIGS. 1 through 3. In FIG. 1 an extrusion 1 is shown attached to a frame member 3 by means of a screw 5 inserted through an aperture formed in the frame member and into a cylindrical channel 7 formed in the extrusion 1, the channel 7 being provided with threads 9 for retainably receiving the threads of the screw 5. In FIG. 2 an extrusion 1 having a vertical slot 11 formed therein is shown attached to a frame member 3 by means of a pin 13 slidably disposed in the cylindrical channel 7 of the extrusion 1, the pin 13 having a head portion 15 and a circular groove 17, the groove 17 being accessible by means of the vertical slot 11 for installing an E-ring retainer 19 thereinto, a helical spring 21 also being disposed on the pin 13 interposed between the leftmost extremity of the slot 11 and the E-ring retainer 19, the function of the helical spring 21 being to resiliently urge the pin 13 to a fully engaged position with respect to the channel 7 such that the head 15 thereof is held in contact with the frame member 3. In FIG. 3 an extrusion 1 having a vertical slot 11 is shown in attached relationship relative to a frame member 3 by means of a headless pin 23 that is slidable in the cylindrical channel 7 of the extrusion 1, the pin 23 also having a circular groove 17 formed therein which is accessible by means of the vertical slot 11 for installing an E-ring retainer 19 thereinto, a helical spring 21 being disposed on the pin 23 interposed between the E-ring retainer 19 and the leftmost extremity (as viewed in FIG. 3). of the vertical slot 11. The helical spring 21 thus biases the pin 23 in an outward direction relative to the extrusion 1 to thereby hold a tip end 25 of the pin into engaged relationship relative to an aperture formed in the frame member 3.
The disadvantages of these prior art attachment methods share the common characteristic of relatively high materials and labor costs. For example the arrangement illustrated in FIG. 1 requires the use of a screw and the performance of an additional machining operation on the extrusion 1, that of forming the threads 9 in the walls of the cylindrical channel 7. The arrangement of FIG. 2, while eliminating the need of a screw, requires still a different additional machining operation on the extrusion 1, that of forming the vertical slot 11, and the performance of a difficult assembly operation involving the installation of the helical spring 21 and the E-ring retainer 19 on the pin 13 within the confined area of the slot 11. The arrangement of FIG. 3 also requires the additional slot-cutting machining operation on the extrusion 1, and the performance of the difficult and time consuming assembly operation referred to above in connection with the FIG. 2 arrangement.